19.1.14電子郵件：示例 - 第5個示例的問題

Question

我試圖從.msg文件中提取附件。 github上的解決方案太詳細了，我不能正確理解，這裏的答案並不盡如人意。在另一個類似於我的問題中指出了這個example，但我一直無法弄清楚這個函數是如何工作的。
我相信我接近，但無法弄清楚它是什麼我768,16與開幕 - 開放（msgFile）爲FP：這是我到目前爲止的代碼：

import os 
import sys 
import email 
import errno 
import mimetypes 

from argparse import ArgumentParser 

def main(): 
    parser = ArgumentParser(description = """\ 
Unpack a MIME message into a directory of files. 
""") 
    parser.add_argument('-d', '-- C:\\Users\\MikeS\\Documents\\ImproveBKFS\\Python\\msg_extract', required = True, 
        help = """Unpack the MIME message into the named 
        directory, which will be created if it doesn't already 
        exist.""") 
parser.add_argument('TestFile.msg') 
args = parser.parse_args() 

with open(args, 'wb') as fp: #issues with open(args) 
    msg = email.message_from_file(fp) 

try: 
    os.mkdir(args.directory) 
except FileExistsError: 
    pass 

counter = 1 
for part in msg.walk(): 
#multipar/* are just containers 
    if part.get_content_maintype()=='multipart': 
     continue 
    #Applications should really sanitize the given filename so that an 
    # email message can't be used to overwrite important files 
    filename = part.get_filename() 
    if not filename: 
     ext = mimetypes.guess_extension(part.get_content_type()) 
     if not ext: 
      #Use a generic bag-of-bit extension 
      ext = '.bin' 
     filename = 'part-%03d%' % (counter, ext) 
    counter +=1 
    with open(os.path.join(arg.directory, filename), 'wb') as fp: 
     fp.write(part.get_payload(decode=True)) 

if __name__ == '__main__': 
    main() 

我被困第20行這裏是我的輸入和錯誤消息。

PS C:\Users\MikeS\Documents\\Python\msg_extract> py -3  get_payload_3.py -d ^V TestFile.msg 
Namespace(C:\Users\MikeS\Documents\Python\msg_extract='\x16', TestFile.msg='TestFile.msg') 
Traceback (most recent call last): 
    File "get_payload_3.py", line 53, in <module> 
    main() 
    File "get_payload_3.py", line 26, in main 
    with open(args) as fp: #something with this line 
TypeError: invalid file:  Namespace(C:\Users\MikeS\Documents\Python\msg_extract='\x16',  TestFile.msg='Test 
File.msg') 

任何輸入或輸入類型的線索我需要給這個函數將是一個巨大的幫助。謝謝

Answer 1

parser.add_argument('-d', '-- C:\\Users\\MikeS\\Documents\\ImproveBKFS\\Python\\msg_extract', required = True, 
       help = """Unpack the MIME message into the named 
       directory, which will be created if it doesn't already 
       exist.""") 

該字符串的用途是什麼：'-- C:\\Users\\MikeS\\Documents\\ImproveBKFS\\Python\\msg_extract'？

使用簡單的東西，比如--dir

parser.add_argument('-d', '--directory', required = True, 
       help = """Unpack the MIME message into the named 
       directory, which will be created if it doesn't already 
       exist.""") 

你解析args後，打印，隨時瞭解解析器發現：

args = parser.parse_args() 
print(args) 

然後，如果你需要這個「目錄」，使用像args.directory。

變化這個問題，以及：

parser.add_argument('TestFile.msg') 

到

parser.add_argument('outfile') 

及用途：

with open(args.outfile, 'wb') as fp: #issues with open(args) 
msg = email.message_from_file(fp) 

我懷疑你的說法混淆了dest（或長選項名稱）使用該值，可以是默認值，也可以是從命令行獲得的值。

'C：\ Users \ MikeS \ Documents \ ImproveBKFS \ Python \ msg_extract'和'TestFile.msg'看起來像一個目錄和文件名。但是它們正在用於add_argument的dest插槽中。您可能需要花些時間閱讀​​文檔，並練習一些更簡單的示例。